The website quickly sought to deflect blame for the leak of the leaked classified cables. It accused the U.K. newspaper the Guardian—which last year was WikiLeaks' partner in publishing some of the cables—of publishing in a book a password that unlocks an encrypted file containing the unredacted cables.
According to German magazine Der Spiegel, the encrypted file has been available online since early this year. In a statement, WikiLeaks didn't explain how the encrypted file slipped from its possession, and it didn't respond to a request for comment.
The fracas has put WikiLeaks in the position of decrying what it called the "reckless" and "negligent" disclosure of information—something WikiLeaks' critics have long accused it of doing itself.
WikiLeaks in recent days has faced criticism for publishing some of the cables without redacting the names of individuals, such as government informants, who theoretically could be jeopardized by publication of the information.
In a statement Thursday, the Guardian said it "utterly rejects any suggestion that it is responsible for the release of the unedited cables."
In its own news story about the situation, the Guardian said its book, published seven months ago, "contained a password, but no details of the location of the files. … it was a meaningless piece of information to anyone except the person(s)" who knew where to find the files online.
It isn't certain who leaked the diplomatic cables to WikiLeaks in the first place, but last year, the U.S. military charged Army intelligence analyst Bradley Manning with illegally taking secret State Department files.
For many months, WikiLeaks published only a fraction of the 250,000 diplomatic cables it said it possessed.
WikiLeaks began publishing batches of the cables in November, intensifying outrage in Washington, where officials already were angered by the group's publication of other classified U.S. documents. The diplomatic cables expose years of U.S. foreign-policy work in countries around the world.
WikiLeaks made the cables available to several news organizations in advance, including the Guardian and Der Spiegel. The New York Times also obtained a copy of the cables, and began publishing them at the same time as WikiLeaks and the other publications. The news organizations and
WikiLeaks say they redacted the cables before publication to remove the names of people around the world who have shared information with U.S. diplomats and could come to harm if exposed.
In recent days, as German media reported that the full set of unredacted cables was online outside of WikiLeaks' control, WikiLeaks scrambled to publish more than 100,000 of its previously unreleased cables.
Some of the newly released cables reportedly contained the names of confidential informants. This prompted new criticism of WikiLeaks, which has come under fire in the past for publishing the names of classified informants, including those in a cache of secret U.S. military documents about the war in Afghaninstan.
Officials from human-rights groups wrote to Mr. Assange last year expressing concern that the unredacted material could put the informants' lives at risk.
Asked about the latest WikiLeaks news Thursday, a State Department spokeswoman said: "We have made clear our views and concerns about illegally disclosed classified information and the continuing risk to individuals and national security that such releases cause. WikiLeaks has, however, ignored our requests not to release or disseminate any U.S. documents it may possess and has continued its well-established pattern of irresponsible, reckless, and frankly dangerous actions."
WikiLeaks' publications have won attention and notoriety for Mr. Assange. But the document-leaking organization he founded also has splintered, with several key members leaving after clashes with Mr. Assange.
Mr. Assange has found trouble on other fronts. He is currently under house arrest in the U.K. fighting extradition to Sweden, where authorities want to question him over allegations that he raped one woman and molested another during a visit to Stockholm last summer.
He hasn't been charged and denies any wrongdoing. Mr. Assange and his lawyers in the past have called the allegations part of a smear campaign aimed at undermining WikiLeaks' work. Swedish officials and a lawyer for the two women say their complaints have nothing to do with WikiLeaks' document-leaking activities.